TW200831278A - Roll of polyolefin microporous film and the producing method thereof - Google Patents

Abstract

A roll of polyolefin microporous film consisting of a roll having a polyolefin microporous film rolled up around a roll core, characterized in that the absolute value ([μm) of difference (film thickness difference) between the film thickness (T, [μm) calculated according to the formula (1) and the film thickness (t, [μm) evaluated for one sheet is 1.5 [mu]m or less. Further, there is provided a process for producing the same. T(μm) = π (D2-d2)/4L (1) wherein D is the outer diameter (mm) of roll resulting from rolling up around the roll core including the porous film; d the outer diameter (mm) of roll core; and L the length rolled up (m) of the roll.

Description

200831278 IX. Description of the Invention: [Technical Field] The present invention relates to a polyolefin microporous film winding for use in a battery separator, that is, a polyolefin or a polyolefin-containing resin composition. The microporous membrane is wound around the core. The present invention relates to a polyolefin microporous film winding which is particularly preferably used as a separator for a lithium ion secondary battery and a method for producing the same. [Prior Art] A polyolefin microporous film is used for various batteries. Isolation membrane. In particular, polyolefin resins are particularly useful in clock ion secondary batteries because of their excellent resistance to organic solvents and excellent electrical insulating properties. In recent years, the use of mobile phones, electric moons, and other portable devices, which are the main applications of lithium ion secondary batteries, has become more versatile, lighter, and more cost-effective. Among them, the rain is quantified and the energy is increased, and the separator film is required to be thinned. On the other hand, since the winding film (electrode/spacer winding) in which the separator and the electrode are wound at the same time is loaded into the outer casing of the battery, the outer diameter of the electrode/spacer winding is required to be excellent. . Recently, large-sized plasma ion secondary batteries have been studied for use in automobiles and storage applications, and the separators used at this time have a wide width and a long coil length. In order to expand the spread of such large-sized lithium ion secondary batteries, it is necessary to produce the outer diameter of the wound material with high precision, and to reduce the defective rate when inserting the outer casing, thereby achieving cost reduction. For example, in the case of the patent document 1, it is proposed to increase the maximum outer diameter and the minimum outer diameter to a specific range in order to improve the workability of manufacturing a battery separator, such as 123124.doc 200831278, etc. ; & ^ ^ , 1 etching film. However, the outer diameter accuracy of the above-mentioned winding is not sufficient. Patent Document 1: Japanese Patent Laid-Open No. 2004-99799 SUMMARY OF INVENTION Technical Problem An object of the present invention is to provide a method for reducing winding of an electrode/separator

The polyolefin microporous film winding which is inserted into the outer casing and which is poorly inserted is further provided. The object of the present invention is to provide a polyolefin microporous film roll which can be controlled by the outer diameter of the electrode/spacer winding. Wrap and its manufacturing method. MEANS FOR SOLVING THE PROBLEMS The inventors of the present invention have not only focused on improving the outer diameter accuracy of the electrode/spacer winding, but it is extremely important to control the polyolefin microporous film (isolation film) wound material as a material thereof. The accuracy of the diameter and the above-mentioned matters have been intensively studied, and as a result, a method for solving the above problems has been found, thereby completing the present invention. In particular, it has been found that the thickness information calculated by the outer diameter and the coil length measured by the cutter roll outer diameter measuring machine disclosed in Japanese Laid-Open Patent Publication No. Hei. The outer diameter of the winding of the electrode is wound together, thereby completing the present invention. Further, the inventors of the present invention have found that the polyolefin microporous film wound on a mother roll (rolled before being cut into a desired width) is cut into a specific width over the total width thereof, and then taken up by winding. In the case where each of the polyolefin microporous membranes is formed into a wound material, in order to improve the outer diameter precision of the wound material, the winding tension of each of the 123124.doc 200831278 windings may be controlled. That is, previously, the polyolefin microporous film wound on the mother roll is cut into a specific width over the entire width thereof, and then the cut polyolefin microporous film windings are taken up. In the case of being wound into a wound, the wound windings may be controlled as a whole while controlling the take-up tension of each polyolefin microporous film or all polyolefins corresponding to a specific winding. The winding tension of the microporous film is controlled to be uniform. According to the study by the inventors of the present invention, it is judged that in such a control method, the winding of the object which is not separately controlled is wound tightly or wound. Loose, unable to control its outer diameter. That is, the present invention is as follows. A polyolefin microporous film wound, which is obtained by winding a poly-smoke microporous film on a winding core, and having a film thickness calculated according to the following formula (1) The absolute value (μχη) of the difference (film thickness difference) between Τ(μπι) and the film thickness ί(μιη) evaluated for one piece is 1·5 μηη or less, T(pm)=7i(D2-d2)/4L (1) (In the above formula (1), D means the outer diameter (mm) of the wound containing the porous film wound on the core, d means the outer diameter (mm) of the core, and L means The length of the winding (m)). Further, the present invention is as follows. A method for producing a polyolefin microporous film wound, comprising the steps of: cutting a polyolefin microporous film wound on a mother roll to a specific width over a total width thereof; and controlling the cutting by one side Each of the polyolefin-made microporous membranes of the specific width 123124.doc 200831278 has a winding tension of each of the wound materials and is wound. EFFECTS OF THE INVENTION When the polyolefin microporous film wound material of the present invention is used, it is possible to manufacture an electrode/spacer integrated winding which has less insertion failure when inserted into a casing. Further, according to the present invention, the thickness can be controlled by the outer diameter of the electrode/spacer integrated type wound material. Further, the production method of the present invention can efficiently produce the above-mentioned polyolefin microporous film wound material. When the method of the present invention is applied to an electrode or the like, the outer diameter control of the electrode/spacer _ body winding can be accurately performed. [Embodiment] Hereinafter, the present invention will be described in detail. [5. Thin-porous microporous film wound product] The polyolefin microporous film wound of the present invention is characterized in that a polyolefin microporous film is wound around a cylindrical core such as a tube. The absolute value (μπι) of the difference between the film thickness μ(μιη) calculated according to the following formula (1) and the scented film t(^m) evaluated for one piece (the film thickness difference) is 1 ·5 μπι or less, T(pm)=7i:(D2-d2)/4L (1) (In the above formula (1), D means the outer enthalpy of the wound containing the porous film wound around the core ( Mm) ' d is the outer diameter (mm) of the core, and l is the winding - (volume length (m)). • When the difference in film thickness (Tet) is more than 15 μηι, the winding of the wound material is too loose, so that when it is used as an electrode/separator winding, the electrode/spacer winding cannot be performed. The outer diameter of the object is controlled, and when it is inserted into the outer casing, problems such as the inability to insert may increase. On the other hand, when the film thickness 123124.doc 200831278 difference (Tt) is less than ·1·5 μπι, the winding of the wound material is too tight, resulting in poor permeability of the wound material and absolute difference in film thickness. The value is preferably 1 · 2 μηη or less, more preferably 1 · 0 μηη or less, and most preferably 0.5 μπι or less. The closer the absolute value of the difference in film thickness (Tt) is to the enthalpy, the less the looseness of the polyolefin or the tightness of the winding of the polyolefin microporous film. In the present invention, the polyolefin microporous film winding It is preferred to wind it slightly tightly. Specifically, it is preferred that the value of T-t (μιη) is -〇.5$T-t<0. In the present invention, the "core" is a core used when the polyolefin microporous film is formed into a wound, and is referred to as a cylindrical shape. As a preferable specific example, a tube such as a paper tube or a plastic tube can be cited. In order to reduce the insertion failure when the electrode/separator winding is inserted into the outer casing, a preferred aspect of the present invention is a polyolefin microporous film winding group as described below: it contains two or more The winding group of the above-mentioned polyolefin microporous film wound obtained by cutting the microporous film made of the polyene film wound on the mother roll, the winding deviation is within 5 mm, and the difference in film thickness ( Pm) The standard deviation of 丨 is 〇·7 μηη or less, and further 〇·5 μιη or less. Here, the term "master roll" refers to a roll that is cut to a width required by the user, and generally has a width of 350 mm or more and further 6 〇〇 mm or more. The winding offset refers to winding a polyolefin microporous film on a winding of a core, and on the total length of the wound polyolefin microporous film, the wound polyolefin micro_ The position of the end of the porous film is shifted. That is, the end portion of the wound polyolefin microporous film is located in the width direction between the portion of the winding "the outer side in the width direction" and the portion located inside the j. Furthermore, it is undoubtedly better that the difference in film thickness is not only for a single package but also for a plurality of rolls 123124.doc 200831278 (winding group) which constitute the total width of the mother. In the present invention, the term "the outer k"D of the wound material comprising the porous film wound on the core refers to the winding of the polyolefin microporous film on the shaft. When the mechanical porous film winding is formed into a cylindrical shape, when the surface is not a perfect circle, the "winding of the wound containing the porous medium wound on the core" is set to The average of the long side of the short side of the cut outer section of the section. Specifically, by the following method, the inner side of the three or more legs at both ends of the wound material can be used, and the method described below can be used at equal intervals along the width direction of the microporous film. At each position, the diameter of the winding is measured and the average value is calculated. The outer diameter D of the polyurea-made microporous film wound of the present invention can be measured, for example, by the measurement in Japanese Patent Laid-Open Publication No. 2006-88255. The device is measured with high precision and high efficiency. Fig.: is a schematic view showing a basic configuration of a mechanism for measuring the outer diameter of the winding. That is, for the laser or the visible light projected by the projector 1 光, the image of the winding 2 is measured and the outer diameter of the winding is measured. As such projectors and receivers, a commercially available laser size measuring machine or a digital size measuring machine can be used. • For example, 'Make 2 sets of projectors_receivers (4) size measuring devices • Move in parallel along the direction of the axis of rotation of the winding 2, thereby measuring all the positions of the windings in the direction of the winding (core) on the line The outer diameter. If the size measuring device is relatively moved with respect to the winding 2, the size measuring device can be moved and the winding 2 can be moved. In addition, according to the measurement of the winding material, 123124.doc 11 200831278, it is possible to make the measurement by traversing the winding material, etc., and it is possible to make a measurement by a new projector or a light receiver. The moving speed of the size measuring device: : The measurement accuracy, measurement time, etc. of the required winding material are properly determined. "The measurement can be performed by cutting the short side of the rectangle and the 2 directions corresponding to the long side. In terms of the measurement range of the winding 2 measured by the size measurement, as long as one of the wounds is continuously measured, the outer diameter at the J ^ position is sufficient. The reason is that the winding

The difference in the outer diameter of the material is due to the overlapping of a plurality of films having a difference in thickness. The profile of the profile P焱T is a/, and is immediately equal to the measurement, which is almost equal regardless of the position. Further, as shown in Fig. 2, an example of the rut when measuring the outer diameter of the winding group of the present invention is shown. In order to operate the dimension measuring machine with high precision, it is preferable to arrange the volume group of objects in the center of the two sets of the light receiving machine 1A and the light receiving machine (3), for example, at the center of the two sets of the light receiving machine 1A and the light receiving machine 1B. A shaft or the like for fixing the cutting roller is provided, whereby the winding group can be fixed by such a method. When the widths of the two sets of the light receiver 1A and the light receiver 1B are moved, it is also possible to simultaneously measure the group of windings composed of the wounds having different diameters. Fig. 3 shows an example of the result of simultaneously measuring such a group of windings composed of a plurality of windings. Part A of the figure is a measurement of the gap between the windings, and preferably has a calculation processing unit that continuously eliminates the discontinuity between the windings from the continuous measurement data between the plurality of windings. section. To this end, the following method can be used: by removing the measured I data of the rise and fall of the measured data, the calculation method of the outer diameter of the plurality of windings is calculated; or by differentially processing the measured data, the external data is removed. The diameter measurement produces a sharp change 123124.doc -12· 200831278 part of the 'calculation of the calculation of the outer winding of a plurality of windings, because it is ideal when it is divided into strips when cutting. It is equipped with a processing unit, 'measurement information and the film strip of the film winding. ^^ ^ The positional relationship of the skin order Beixun is the same, and the information display mechanism. Measurements are also available in the device

= The so-called "thickness t evaluated by the film" is:,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, The outermost microporous J' of the wound film of the porous film is measured at a plurality of positions at equal intervals in the width direction, and the average value of the nose is 9. In the present invention, the film of the microporous film made of a polysulfide is used. The thickness measurement method is limited, for example, in addition to the method shown in the following embodiments, it can also be measured with high precision by the method described below, that is, the measurement terminal is placed on the micro-film , read its action and convert it into film thickness. An optical detector can be used, for example, during the reading of the action of the measuring terminal. Further, it is preferred that the pressure per unit area carried by the microporous membrane is controlled within a fixed range by measuring the terminals. Further, it is preferred to perform measurement in a constant temperature chamber. Fig. 6 is a side view showing a basic constituent member of an example of a device for measuring the film thickness t of the microporous film. A terminal fixing portion 25 and an optical detector fixing portion 29 are attached to the pillar 22 provided on the support table 2A. Hereinafter, a method of measuring the film thickness t of the microporous film with high precision will be described with reference to Figs. 7 and 8 . Fig. 7 is a view showing a state in which the microporous film is placed on the sample stage 23. Fig. 8 is a view showing a state in which the measurement terminal rod 24 is placed on the microporous film. As shown in FIG. 7 and FIG. 8, the microporous film 37 as a measurement sample is placed between the sample stage 23 and the measurement terminal rod 24, and the measurement terminal rod is manually moved up and down the indicator rod 25, thereby measuring the terminal rod 24. The microporous film 37 is held by the sample stage 23, and the optical detecting unit 3 detects the pressure adjusting portion fixing portion 32 directly coupled to the measuring terminal rod 24 by using reflected light from the pressure adjusting portion fixing portion 32 or the like. Move up and down, convert it to a film thickness, and read the film thickness. Regarding the measurement technique of the optical detection unit, for example, as described in the catalogue of the key internals of the Keyenee & Division, the confocal measurement method, the triangulation method, the automatic alignment method, the optical wave ranging method, etc. can be used. the way. In the best case, an optical detector using a triangulation method is desirable. The triangulation method is a method in which a part of the diffused reflected light on the surface of the object of the projected laser light is condensed on the light receiving lens and imaged on a CCD (Charge c〇uPle device). Wherein 'when the object is displaced, the concentrating angle of the diffused reflected light shifts' the imaging position on the CCD moves, and at this time, the movement is detected, the amount of movement is converted into a value corresponding to the film thickness, and the amount of movement is read. As the film thickness. Preferably, the resolution of the optical detecting portion 3 used at this time is 1 ’, more preferably 〇 1 μϊη or less, and even more preferably 0 〇 i or less. Further, it is preferable that the microporous film 37 is sandwiched between the measuring terminal rod 24 and the sample stage 23, and the measurement is performed after a predetermined period of time, for example, 5 seconds to 1 minute, preferably 5 to 3 seconds. As a specific example of a preferable optical detector, lk_G15 manufactured by Keyence Corporation can be cited. In order to measure the thickness of the microporous film with good reproducibility and precision, it is important that the table 23 is parallel to the measuring terminal rod 24. For this reason, it is preferable to measure the terminal parallelism adjusting member 27 as shown in Fig. 6, so that fine adjustment can be performed. More preferably, after the level of the sample table 23 is leveled, the parallelism between the sample stage and the measuring terminal rod is adjusted. The diameter of the measuring terminal rod is not particularly limited, and is preferably 1 to 20 mm, more preferably 1 to 1 mm. The case of Fig. 6 to Fig. 8 is used as a measuring terminal, and the diameter is $ mm. 'and its verticality has been checked. Further, in the case where the operation of measuring the terminal rod is read by the optical detecting portion, it is desirable to measure the film thickness in the constant temperature chamber so that no coma is generated. Further, in order to measure the thickness of the microporous membrane with good reproducibility and precision using a plurality of measuring devices, it is preferable to fix the pressure of the measuring wheel rod contacting the microporous film. In the example of FIGS. 6 to 8, a pressure receiving portion 28 is provided on the upper portion of the analog display portion 26 such as the measuring terminal rod % for placing a weight for adjusting the pressure of the measuring terminal rod 24, and The pressure of the measuring terminal rod % is adjusted to be fixed, and is fixed by the pressure adjusting portion fixing portion U in the example of FIGS. 6 to 8 so that the pressure measuring portion 28 can be adjusted by the pressure adjusting portion 28. The pressure is applied, and as shown in Fig. 7, the measurement terminal rod % is formed as a body inside the analog display portion 26. As another method for making the measurement end = the pressure of the rod 24 specific, for example, the weights of the measurement terminal rods used in the plurality of measuring devices themselves may be the same. [Method for Producing Polyolefin Microporous Film Winding] The polyolefin microporous film winding of the present invention which has no winding slack or excessive winding tightness and high outer diameter precision can be obtained by the following means Manufacture: Pair of polypropylene microporous membranes wound on a mother roll, 123124.doc -15- 200831278, which are cut to a specific width over the entire width thereof, and then, the polyolefin microporous membranes to be cut out When wound around a winding core, the winding tension of each of the wound materials composed of the polyolefin microporous film is controlled.方法 The method of controlling the winding tension of each winding is not limited. For example, the winding tension of each of the wound materials can be controlled and controlled by winding each of the cut polyolefin microporous membranes into separate volumes having respective rotary driving portions. On the core, the winding cores are rotated by the respective rotation driving portions, thereby controlling the winding tension of each of the windings. Further, when the cut polysulfide microporous film is wound around a core having a common rotary drive portion or a plurality of cores fixed to a rotary pump having a common rotary drive portion In this case, a separate tension control device may be separately provided for each of the polyolefin microporous membranes to control the winding tension of each of the wound materials. The winding of the present invention can be preferably obtained, in particular, by cutting a polyolefin microporous film using a separate driven cutter and winding the roll on a core. Since the individual drive cutter can perform the tension control on each of the cutter rolls when the total width of the mother rolls is cut, it is suitable for efficiently producing the polyolefin microporous film wound of the present invention. • As an example of a single drive cutter, there is a cutter having a plurality of drive transmissions 6 as shown in FIG. The drive transmission unit 6 is connected to a roller 9 that is moved by a shared AC (alternating current) motor, for example, by a magnetic powder dispenser, and is wound around a tube (not shown) provided in the tube clamp head 8. This can be done by driving the timing bA 7 or the like and driving the drive 123l24.doc -16-200831278. In the case of a magnetic powder clutch, an electrical signal can be used to control its output torque. Therefore, by performing tension detection for each of the individual official winding portions and applying electrical feedback, the winding can be performed in accordance with the tension of each individual tube winding portion. Fig. 5 is a schematic view showing such a device. The polyolefin microporous film 'before cutting before being taken out from the mother roll π is cut into a desired width by the cutter 14, and wound around a single arm portion 13 (each separate winding portion) and shared by the shaft ( Not shown) on the supported tube. In contrast, when the prior coaxial drive type cutter cuts on the total width of the mother and winds on the tube having the shared take-up portion, it matches the specific volume of the adjacent plurality of windings. The tension control is performed around the object, so that the obtained wound material is wound tightly or loosely wound, so that it is difficult to control the outer diameter, and it is difficult to obtain the wound material of the present invention well. Moreover, the winding offset is also likely to occur. Furthermore, the so-called single drive cutter of the present invention is a device for cutting and winding a web, which means that the cut webs are wound on separate cores each having a rotary drive portion. . When the polyolefin microporous film is taken up, the take-up tension is preferably such that the take-up tension of the mother roll is about 125 (N/m) or less, so that the winding tension of each of the wounds is substantially equal to the take-up tension (Comparative) Good is within ±20%). The specific value of the take-up tension can be determined, for example, by changing the take-up tension within the above range and performing a plurality of windings, and measuring the winding tightness of the obtained wound product, and determining the result based on the result. In the present invention, the tightness of the polyolefin microporous film wound is less than 34 N at a distance of 5 mm from the roll anger. When wound around the tightness and the roll 123124.doc -17- 200831278, the winding shape of the winding is poor. Further, it is preferred that the polyolefin microporous film is wound at a distance of 1 mm from the core (F(10)) and at a distance of 20 mm from the core (F(20) The difference (F(10)_F(20)) is 0·05 N or more and 2 N or less. When the value of F(10)-F(20) is within this range, defects such as winding deviation and misalignment can be reduced.

Here, the tightness of the winding is one of the indexes for evaluating the winding state of the wound, meaning that the diameter of the front end is 〇·〇4~〇·〇7 mm, and the tip angle is 25~ 27. The needle tip R is the force (N) required for the needle to be inserted into the side of the winding 1 cm from 〇·〇4~〇·〇7 mm. Further, the distance from the winding core means the distance from the side surface of the winding body in the direction perpendicular to the tangential line of the winding core section (circle). The tightness of the volume and the object can be, for example, based on the "Smith • (4) tightly described in the quality of the winding roller of the "Scissor/Winding Machine Simple Basic Technology Lecture, I. The measurement method was measured by the following method. Fig. 9 is a schematic view showing an apparatus for measuring the tightness of a wound. The tightness measuring device 1G1 of the wound body is to mount the needle on the force meter. The tightness of the winding can be measured by taking the front end of the measuring device ι〇ι into the measuring position and pressing the measuring device 101 vertically until the needle is inserted into the icm, and the peak value is measured. Load. As such a device, for example, it is possible to use the needle side of the safety pin "gw's if38 face" manufactured by Kokuyo, and then install it in Japan's metering industry (10) an """η Μ""Μ6" C°. The digital dynamometer of Ltd.) is purchased from 123124.doc • 18 - 200831278. Further, when a separate drive type is used, the 丨4 is also cut and wound on the mother roll. In the case of producing a poly-porous microporous film, when a poly-[*] porous film winding is produced, it is possible to provide a winding material which can further reduce the insertion of the electrode/separator-type winding body into the outer casing. It is preferable that the film is calculated according to the following formula (1) in a group of windings in which the winding of the mother roll S__ is browned to within 5_ of the total width of the mother roll. Thick TQm, 盥 marriage L u ^ Ημιη) and the thickness of the film evaluated

标准μηι) The standard deviation of the difference (film thickness difference) is 0. 7 μπι or less, more preferably 〇·5 jim or less, T(pm)=7c(D2_d2)/4L (1) (in the above formula (1) 'D' refers to the outer diameter of the wound containing the porous film wound on the core (referred to as '(10) means the outer diameter of the core) to mean the length (m) of the wound. In the present invention, the winding core for winding the polyolefin microporous film preferably has an outer diameter of 9 · 8 or more (five) or more in terms of winding property and cost. The core used is usually referred to by the inner diameter. A paper tube having an outer diameter of 91·8 mm usually has an inner diameter of 76·2 mm and a paper thickness of 5 to 15 (five), which can be adjusted according to the strength. As the tube to be used, a commercially available paper tube having a tolerance of ±0.5 mm and more preferably ±〇·3 mm, or a plastic tube can be used, and it is preferable that the tolerance is smaller. The winding of the present invention will exert an effect of providing an electrode/separator-type winding wound which can reduce insertion failure when inserted into a casing, and can be used as a separator having a wide width (for example, 6 〇 to 160 mm). ), the film with a long coil length (for example, 500 to 3000 m, preferably 800 to 2500 m) of electricity 123124.doc -19- 200831278 pole • when the separator is wound and used, the above effect is special obvious. When the polyolefin microporous film wound of the present invention is used, it is possible to provide an electrode/separator winding as described below, that is, a winding for winding a polyolefin microporous film on a winding core. The outer diameter of the wound material including the porous film wound around the winding core and the film thickness (μηι) calculated from the outer diameter and the coil length of the winding core can be clarified, thereby reducing the time when the outer casing is inserted. Poor insertion. [Polyolefin-made microporous film] The polyolefin microporous film of the present invention preferably has a pore diameter of μηι, more preferably 〇·〇ι~〇·ι μιη. In the present invention, the pore diameter Γ(μπι) of the microporous membrane is as follows: it is known that the fluid inside the capillary is in a Knudsen flow when the average free path of the fluid is larger than the pore diameter of the capillary, and is smaller than the pore diameter of the capillary. According to the p〇iseuille flow 'use this point', the air flow in the gas permeability measurement of the microporous membrane is assumed to be a normal flow 'and' the water flow in the permeability measurement of the microporous membrane is assumed to be The plug flows and is represented by the following formula: r = 2vx (Rliq / Rgas) x (16n / 3Ps) x 106. Here, Rgas is the air transmission velocity constant (m3/(m2.sec.pa)), Rliq is the water transmission velocity constant (m3/(m2, sec*Pa)), and v is the molecular velocity of air (m/ Sec) 'η is the viscosity of water (Pa*sec) (=0.8950 mPa.sec at 25°C), and Ps is the standard pressure (Pa) (=101325 Pa), which can be expressed by the following formula:

Rgas=0.0001/(Air permeability χ(6·424χ10-4)χ(0·01276χ 101325)). Furthermore, the air permeability is determined according to JISP-8117: 123124.doc -20- 200831278

Rliq = water permeability / 100. Further, the water permeability can be obtained as follows. The microporous membrane preliminarily impregnated in ethanol is placed in a non-recorded steel liquid permeable unit having a diameter of 41 mm. After washing the ethanol of the membrane with water, the water is passed through a pressure difference of about 50,000 Pa. The amount of water permeation (Cn^, calculate the unit time, unit pressure, per unit area of water permeability, and use this as the water permeability: ' ν = ((8 ΙΙχΤ) / (π χΜ)) 1/2. Φ Again, R is a gas constant (=8·314), Τ is an absolute temperature (κ), π is a pi, and Μ is an average molecular weight of air. The porosity of the polyolefin microporous film is preferably 25% or more and 75% or less. Here, the void ratio (./.) can be expressed by the following formula: void ratio (%) = [{V - (M / p)} / V] xl 〇〇 where v is the volume of the microporous membrane (cm3), M is the mass of the microporous membrane (g) 'P is the density (g/cm3) of the resin or resin composition constituting the microporous membrane. Specifically, for example, it can be calculated by the following method: A sample of 10 cm×l〇cm square was cut out from the microporous membrane to determine the volume (cm) and mass (§), based on the volume (cm) and mass (g), and the polyolefin constituting the membrane. The viscosity of the fat composition (g/cm3) is calculated by the above formula. Further, in the case where the microporous film contains polyethylene, the density of the polyethylene is 〇. Further, the film thickness t of the polyolefin microporous film is preferably 3 μχη or more and 2 μμχη or less. The directional friction coefficient of the polystyrene-made microporous film in the TD direction is preferably 〇. 6 Below, more preferably 〇·1~〇·4. The dynamic friction coefficient in the TD direction can be measured, for example, 123124.doc -21 - 200831278. For the sample with a width of 50 mmx and a measurement direction of 200 mm, use Kato Tech Limited The company manufactures iKES-S]E friction testing machine with a load of 50 g and a contact area of 1〇xl〇=1〇〇mm2 (wound wire with 2〇〇·5 _) and a joint transmission speed of 1 mm. The measurement is carried out under the conditions of /sec, the tension of 6 kPa, and the temperature of 25 ° C. Further, the polyolefin microporous film having a dynamic friction coefficient of 0.1 to 0.4 in the TD direction is liable to cause a winding offset or the like. Preferably, the winding method of the winding material of the present invention is used for winding. In the case of the object, the microporous film is easily damaged in the winding which is excessively tightly wound, and when used as a separator for a battery, the proportion of defective dielectric strength will increase. This tendency is particularly The high anisotropy microporous film having a tensile strength in the longitudinal direction and the transverse direction of the axial extension is significantly more than 10 times. Therefore, the winding-free tight wrap of the present invention and the method for producing the same are particularly suitable for use in the longitudinal direction. The ratio of the tensile strength (MD tensile strength) in the direction to the φ tensile strength (10 tensile strength) in the width direction (MD tensile strength/TD tensile strength) is 10 or more as a polyolefin microporous film. situation. The polyolefin microporous film used in the present invention can be produced, for example, by the following method. As the polyolefin, a polyolefin alone and two or more kinds of polyolefin-hydrocarbon mixtures can be used. Examples of the polyolefin which is a main component include polyacetonitrile, polypropylene, poly-4-methylpentene and the like. The polyolefin other than the main component can be blended with various polyolefins within a range that does not impair the film forming property and does not impair the object of the present invention. For example, it can be adjusted to improve the pore blocking characteristics of the heart. 123124.doc -22- 200831278 Low-melting point polyethylene with higher content of smoke comonomer, or polypropylene for improving heat resistance and poly-4-A Base-1-pentene and the like. Further, a polymer material other than polyolefin or other organic and inorganic materials may be blended in a range which does not impair the performance of the battery separator, does not impair the film forming property, and does not impair the purpose of the invention. In the polyolefin composition constituting the microporous film, if necessary, an antioxidant such as a phenol type, a phosphorus type or a drip system, a metal soap such as calcium stearate or stearic acid, or an ultraviolet absorber or a light absorber may be used. Known additives such as stabilizers, antistatic agents, antifogging agents, dyeing pigments, and the like. The method for producing the polyolefin microporous film of the present invention is not particularly limited, and a so-called dry method, wet method or the like can be employed. As a manufacturing method by the so-called wet method, for example, a polyolefin-made porous film can be produced by dissolving the above-mentioned polyolefin at a temperature equal to or higher than the melting point in a granule called a plasticizer. The obtained solution is cooled to a temperature lower than the crystallization temperature to form a south molecular gel, and the polymer gel is used for film formation (film formation step), and the obtained film is stretched (extension step), after which the plasticizer removal is removed. step). Here. The plasticizer means an organic compound which can form a uniform solution with a polyolefin at a temperature below its boiling point, and specific examples thereof include decahydronaphthalene, monomethylbenzene, dioctyl phthalate, and phthalic acid. Dibutyl acrylate, stearyl alcohol, oleyl alcohol, decyl alcohol, decyl alcohol, diphenyl ether, n-decane, n-dodecane, paraffin oil, and the like. Further, a plasticizer which is regenerated from the step of removing the plasticizer may also be used. The ratio of the (4) in the molecular gel is not particularly limited, and is preferably from 20% by weight to 9% by weight, more preferably from 5% by weight to 8% by weight. If the ratio of the plastic 123124.doc -23-200831278 agent is 20% by weight or less, there is a tendency that it is difficult to obtain a microporous film having an appropriate void ratio; if it is 9% by weight or more, the heat: liquid: viscosity is lowered' There is a tendency that the sheet is difficult to continuously form. Hereinafter, an example of a method for producing a polyolefin microporous film is divided into the above-described film forming step, stretching step, and plasticizer removing step. '[Film Forming Step] The film forming method is not particularly limited. For example, the ring-mixed polyolefin powder and the plasticizer are supplied to the extruder at a temperature of about 2 rc. After melt-kneading, 'the usual hanger mold (plus ^4) die is cast onto the cooling roll, and the film seal having a film thickness of several tens of nanometers to several millimeters can be continuously formed. [Extension step] Then, the obtained The sheet is stretched in at least a uniaxial direction to form a stretched film. The stretching method is not particularly limited, and a tenter method, a parent method, a calendering method, etc. may be used. Among them, it is preferred to carry out the two-axis method by the tenter method. The elongation temperature may be from the normal temperature to the melting point of the polymer gel, preferably 80 to 140 ° C, more preferably *1 〇〇 to 13 〇 t: the stretching ratio is better, The area magnification is 4 to 400 times, more preferably 8 to 2 times better. It is 16 to 100 times. If the stretching ratio is 4 times or less, it is used as a separator... The strength is not sufficient, if it is 4〇 If it is more than 〇, there is a microporous film that is not only difficult to extend but also The tendency of the void ratio is low, etc. [Plasticizer removal step] Then, the plasticizer is removed from the stretched film, whereby the microporous film can be obtained. The method of removing the plasticizer is not particularly limited. For example, using paraffin oil or邻123124.doc -24 - 200831278 When dioctyl phthalate is used as a plasticizer, it can be extracted by using an organic solvent such as dichloromethane or methyl ethyl ketone, but it can also be obtained by The microporous μ' is subjected to superheat drying at a temperature below its melting point temperature, and is sufficiently removed. Further, for example, low fossilization using decahydronaphthalene or the like: as a plasticizer, only the melting temperature of the microporous membrane The following temperatures can be removed by heating and drying to achieve low cost, and the used organic solvent can be recovered and reused for removing the plasticizer. To improve the permeability,

It is also preferable to increase the dimensional stability, and the polyolefin microporous film obtained by the above-described production method is subjected to heat treatment at a temperature equal to or lower than the melting point temperature as necessary. EXAMPLES Hereinafter, the present invention will be specifically described by way of Examples and Comparative Examples, which are not intended to limit the scope of the invention. The various physical properties used in the present invention were measured in accordance with the following test methods. (1) A film thickness of 25 cm was measured from a microporous membrane that was cut out, and a micro-thickness device (KBM type) manufactured by Toyo Seiki was used at room temperature of 23 ° C for 10 The measurement is performed, and the average value is taken as t. (2) The film thickness calculated from the outer diameter of the grip and the winding core of the porous film and the winding length of the wound core, and the outer diameter described in Japanese Patent Laid-Open Publication No. Hei 2__88255 The measuring device 'measured the outer diameter D (mm) of the microporous film containing polyolefin which was cut and wound on the core coffee (4) having the outer diameter measured in advance. If the winding length is L(m), it can be obtained by the following formula 123124.doc -25- 200831278

T is determined by T(Hm)=7C(D2_d2)/4L. The measurement of the outer diameter D of the microporous membrane is carried out in a polyolefin-made micro-multiple in which the width is 1 mm in a single-pack S-cut and wound, and is measured in a wide position in order to avoid the projections at both ends. The outer diameter of the portion 3 mm from the inner side from the both ends, and the average value is taken as D. (3) Preparation of Electrode/Separator Winding and Preparation of Positive Electrode··92 2% by weight of lithium cobalt composite oxide Lic〇〇2 as scalloped graphite of biobe, respectively, 2.3% by weight And acetylene black as a binder, and 3.2% by weight of polyvinylidene fluoride (PVDF) as a binder, dispersed in N-mercaptopurine (NMp) to prepare a polymer. This slurry was applied to a single surface having a thickness of 2 Å as a positive electrode current collector using a ruthenium coater, dried at 13 Torr for 3 minutes, and then formed by a roller press. At this time, the active material coating amount of the positive electrode is 25 〇 g/m 2 , and the total amount of the living animal is 3 G () g / em 3 . It is cut into widths to form a band. Preparation of the negative electrode: 96.9% by weight of artificial graphite as an active material, 1,4% by weight of ammonium salt of carboxymethylcellulose and 1.7% by weight of styrene-butadiene copolymer gum as a binder, Disperse in a pure water towel to prepare a slurry. Using a die coater, the slurry was applied to one side of a copper foil having a thickness of 12 μm as a negative electrode collector, and dried at 12 Torr for 3 minutes, and then passed through a roll.

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123124.doc :/, Berry attached! Hook ιυο g/m2, . Cut it into a width of about -26-200831278 electrode • separator winding preparation: the above microporous membrane separator, strip positive electrode and strip negative electrode 'with ribbon negative electrode, separator, ribbon positive electrode, . The order is superimposed and wound in a plurality of turns to form a spiral shape, thereby producing an electrode/spacer winding. " (4) Electrode* The outer casing of the separator winding is inserted and clamped by the chuck, and inserted into the prepared 18 ππηφ casing by the casing inserter. The above windings were evaluated. Climbing the casing is poorly inserted. The best volume under the 100-volume roll is below 2 rolls. Good Others Not good. (5) Viscosity average molecular weight Μν The ultimate viscosity [η] at 135 ° C of the polyethylene used in the examples and the comparative examples in the decalin solvent was determined according to ASTM-D4020, and was calculated by the following formula. The viscosity average molecular weight Μν. φ [η]=6·77χΐ〇-1 (Τ4Μν··67 (6) The tightness of the wound material is cut from the needle side of the safety pin "hin-Ι3" made by Kokuyo, 38 mm, and mounted on a Japanese meter. Industrial (unit) digital dynamometer HF-10, ” · Form the measuring device. Put it into the side of the winding and press it vertically until the needle is inserted 1 cm, and measure the peak load. Kokuyo's safety pin "hin·13" has a tip end shape of 3 8 mm on the needle side. The tip angle is 26. The tip R is 0.04 to 0.07 mm, and the tip of the needle is straight and then 〇·〇 47 mm. 123124 .doc -27- 200831278 (7) Air permeability (sec/100 cc) Measured according to JIS P-8117 using a Gurley type gas permeability meter (Toyo Seiki Co., Ltd., G-B2 (trademark)). (MD tensile strength / TD tensile strength) This is a tensile testing machine manufactured by Shimadzu Corporation according to JIS K7127.

Auto Graph AG-A (trademark), measured the tensile strength of the sample for tensile strength measurement and the sample for TD tensile strength measurement (shape, width 10 mm x length 100 mm). Use a ce!1〇phane tape (manufactured by Nitto Denko Corporation, trade name: N·29) with a distance between the chucks of 5〇mm' and on both sides of the sample (25 mm each) In order to prevent the sample from slipping during the test, a gas of a thickness of 1 is applied to the inside of the chuck of the tensile tester. The tensile strength (MPa) was determined by dividing the cross-sectional area of the sample before the test, and the ratio of the tensile strength of the MD to the value of the tensile strength of the TD was calculated. Furthermore, the measurement is performed at a temperature of 23 ± 2 ° C, a chuck pressure of 0.30 MPa, and a tensile speed of 200 mm / min (if it is impossible to ensure a distance of 50 mm between the chucks, the deformation speed is 400% / min) Under the conditions of ). [Example 1] [Production of polyolefin microporous film] A mixture of 35 wt% iMv of 270,000 polyethylene and 65 wt% of Mv of 950,000 polyethylene was dry-blended using a roll mixer to obtain Polyolefin composition. The obtained 30% by weight of the composition and 70% by weight of the liquid stone soil were uniformly melt-kneaded by a twin-screw extruder to obtain a polyethylene melt kneaded product. The melt-kneading conditions were as follows, the set temperature was 123124.doc -28 - 200831278 200 C, the number of screw revolutions was 170 rpm, and the discharge amount was 15 kg/hr. Then, the melt kneaded material was held at 22 (rCiT mold (width: 25 〇mm), and the melt kneaded material was extruded into a sheet shape. The molten kneaded material was pressed using a metal roll whose surface temperature was controlled to 60 ° C. 'And cooling it, thereby obtaining a gel sheet having a thickness stability of 1 〇〇〇μχη. Then using a simultaneous biaxial stretching machine at an extension temperature of 125. 〇 extends to 7x7 times 'and then' It is introduced into a methyl ethyl ketone tank, filled with methyl ethyl ketone for secondary collapse, and extracted to remove liquid paraffin. Thereafter, it is dried to remove methyl ethyl ketone. The inlet surface is stretched by using a tenter stretching machine. 〗2〇.〇 Extension 1 · 5 times, heat-fixed at 125 ° C, to obtain a microporous membrane with a lateral width of 12 m, a film thickness of 18 μηη, a porosity of 40%, and a pore diameter of 〇·〇5 μιη Further, the dynamic friction coefficient of the microporous film in the TD direction is 〇.4 [Production of the polyolefin microporous film wound material] In order to make the microporous film made of polysulfonated hydrocarbon finely cut into a plurality of strips Tension control can be performed separately on a plurality of cores, and in separate volumes "In the 卩 Χ 张力 tension detector, by which the tension of each finely cut polysulfide microporous membrane can be separately detected, and the output torque of each driving source is controlled according to the detected value. Using a separate driving slitter, The prepared polyolefin microporous film was cut into a width of 60 mm, and wound around a paper tube (size: 3 Å) to obtain a polyolefin microporous film wound. The d and L were 102 mm, respectively. 1000 m. Cut 8 mother rolls to make a IO60 roll of polyolefin microporous film winding, 123124.doc -29- 200831278. Extract from it, measure and calculate T to be 17.6~18·1 to produce more than 5 mm The winding offset winding has only one roll of 150 rolls with a winding offset of less than 5 mm, and the result is D·T, T, 1 The maximum value is 1·2μιη, the standard deviation is F(5), the average value is 25 N, F(10)_F(2〇)i is the average value μπι, and t is 17~19 0·4 μπι 〇 1 Ν. Furthermore, the cutting width of the cutting machine is set relative to the total width of the mother roll ^ m '

The force is 100N, and the tension of each winding with a width of 6〇mm is controlled to 5 N 〇... [Preparation and evaluation of electrode/separator winding] Electrode according to (3) • Coil winding The crucible electrode and the separator winding were produced, and then evaluated according to (4) the outer casing insertion property of the electrode/separator winding, and as a result, the defective product was 〇, which was regarded as the best. [Comparative Example 1] The polyolefin microporous film produced in Example i was cut into a width of 60 mm using a coaxial slitter, and wound on a tube (size: 3B) to obtain a polyolefin micro Porous film winding. d, L are ι〇2 _, 10 0 0 m 〇 cut 9 mother rolls, and make 180 rolls of polyolefin microporous film windings, resulting in a winding offset of 5 mm or more. volume. The winding cut of 15 windings with a winding offset of less than 5 mm is taken, and D, τ, and t are measured, and the result is:]) is 180.2~183.9 mm, Ding is 17 2~18 5, The maximum value of lT_tl is h6 μιη, and the standard deviation is 〇8 μπι 〇123124.doc -30- 200831278 Furthermore, the so-called coaxial cutting machine used in this comparative example refers to the net after cutting. The objects are alternately separated and wound together on a plurality of winding cores fixed to two rotating shafts having a rotary drive portion. With respect to the total width of the mother roll and the width of 1 · 2 m, the extraction tension of the slitter is 1 〇〇 N, and the winding tension of the winding is 50 N with respect to each rotating shaft, not for each roll. Winding into the 'winding tension control. - The insert casing outerness was evaluated in the same manner as in Example 1, and as a result, 3 rolls of defects were produced, which was considered to be poor. W [Example 2] [Production of polyolefin microporous film] Using a roll mixer, 35 weight was used. The Mv of /0 is dry blended with a mixture of polyethylene of 270,000, and 聚乙烯%2Μν of 95,000, thereby obtaining a polyolefin composition. The obtained 3% by weight of the composition and 70% by weight of the liquid paraffin were uniformly melt-kneaded by a twin-screw extruder to obtain a polyethylene melt-kneaded product. The melt kneading conditions were as follows, the set temperature was ❿ 2 〇〇 ° C, the number of screw revolutions was 170 rpm, and the discharge amount was 15 kg / hr. Then, the melt kneaded product was held in a 22 〇t:iT mold (having a width of 25 〇 mm), and the melt kneaded product was extruded into a sheet shape. Using a metal roll whose surface temperature is controlled to 6 ° C, the melt-kneaded material is pressed and cooled, thereby obtaining a gel sheet having a thickness of 1100 μη 2 and a stable and qualitative property. And, using a simultaneous biaxial stretching machine, extending to a temperature of 7×7 times at an extension temperature, and then introducing into a mercaptoethyl ketone tank, fully dipping in methyl ethyl ketone to extract and remove liquid sarcophagus, After drying, remove methyl ethyl 123124.doc -31- 200831278

Further, using a tenter stretching machine, it was extended by 1.5 times in the transverse direction at 120 ° C, and heat-fixed at 125 ° C to obtain a lateral width of 1.2 m, a film thickness of 20 μm, and a void ratio of 40%. A microporous membrane having a pore diameter of 0·05 μm. Further, the dynamic friction coefficient of the microporous film in the TD direction was 0.4. [Production of Polyolefin Microporous Film Winding] Using a separate driving slitter, a polyolefin made by the above method was used.

The microporous film was cut into a width of 60 mm and wound around a plastic tube (size: 6B) to obtain a polyolefin microporous film wound. d, l are 15 〇 mm, 10 〇〇 m 〇 respectively, and 8 mother rolls 8 are cut to produce 160 rolls, and there are 2 rolls of windings which produce a winding offset of 5 mm or more. The winding cut of 15 windings with a winding offset of 5 mm or less was taken, and β, T, and t were measured and calculated. The result was 216 2 to 219 3 mm, and D is 19 〇~] μΠ1. The maximum value of 19.7~Μ1, lT_t| is 1·4, and the standard deviation is 〇.3 μιη. Further, the average value of F(5) is % N, f(1〇)_f (four) is equal to 0.9 N 〇, and the total width of the mother roll is 1 > 2 m, and the extraction tension of the slitter is 100. N, the tension of each winding of 60 mm width is controlled to 5 N. [Preparation and evaluation of the electrode/separator winding material] The production of the electrode/spacer winding according to (7), the separator winding, and then the evaluation of the (4) electrode/spacer outer insertion property, the result For the bad goods, it is considered good. [Comparative Example 2] 123124.doc -32 - 200831278 The polyolefin microporous film produced in Example 2 was cut into a width of 60 mm using a coaxial slitter and wound on a tube (size, etc.; 6B). In order to obtain a polyolefin microporous film winding, d and L were cut into 9 mother rolls of 150 mm and 1000 in, respectively, and 180 rolls of polyolefin microporous film windings were produced to produce rolls of 5 mm or more. There are 8 rolls of winding around the offset. The wound cuts with a winding offset of 5 mm or less were taken, and d, τ, and t were measured and calculated. The result was: D was 215·5 to 220.1 mm, and T was 18.2 to 20·7 μηη. t is 19.7~21 μηι, | T_t | has a maximum value of 19 μπι, the standard deviation is 〇8 μιη 〇 and then the total relative to the mother is 1 · 2 m, and the extraction tension of the slitter is 100 N. The winding tension of the winding is 5 〇N with respect to each of the rotating shafts, and the winding tension control is not performed for each of the windings. The winding outer casing insertability was evaluated in the same manner as in Example 1, and the result 'produces 3 rolls of defects' was considered to be poor. [Example 3] 12.8% by weight of polyethylene was 270,000, 192% by weight of 1 ^^ was 950,000 ultrahigh molecular weight polyethylene, and 48% by weight of dioctyl phthalate (DOP) ), 20 weight. /. After the fine powder of cerium oxide is mixed and granulated, it is melt-kneaded by a twin-screw extruder equipped with a T-die at the front end, and then extruded, and rolled by a roller heated from both sides to form a thickness of 11 〇μπΐ2 pieces. shape. The bile and the micro-powder were removed by extraction from the molded product to prepare a microporous membrane. Two microporous membranes were overlapped, and 11 (rc extended 45 times in the longitudinal direction, then 'at 133. (: 1 in the transverse direction) 7 times, and finally, 135. The heat was 123124.doc-33· 200831278. A microporous membrane having a lateral width of 1.2 m, a film thickness of 18 μm, a porosity of 50%, and a pore diameter of 〇·ι μπι was obtained. Further, the dynamic friction coefficient of the microporous membrane in the TD direction was 0.2. Production of polyolefin microporous film wound material] The polyolefin microporous film produced by the above method was cut into a width of 60 mm and wound around a plastic tube (size: 3B) using a separate driving slitter On the basis of this, a polyolefin microporous film winding was obtained. d and B were 102 mm and 100 mm, respectively, and 8 mother rolls were cut to produce 160 rolls of polyolefin microporous film winding, resulting in 5 mm. The winding of the above winding offset has 2 rolls. The winding of the unwinding roll is offset within 5 mm, and the D, T, and D are measured and calculated. The result is: D is 18 1.2~183.2 Mm, T is 17.6~18·2 μηι, t is 17~19 μιη, the maximum value of |T_t| is i.3 (four), and the standard deviation is 〇5 μηι. The average value of F(5) is 25 N, and the average value of F(1〇)_F(2〇) is 2 N. Furthermore, the total width of the mother's width is i.2, and the extraction tension of the cutting machine is set. For 100 N, the core tension of each winding of 60 mm width is controlled to 5 N 〇 [Production and evaluation of electrode and separator winding] According to (3) Electrode • Separator winding The electrode/separator winding was produced, and then evaluated according to (4) the outer casing insertion property of the electrode/separator winding, and the result was that the defective product was i, which was considered to be good. [Comparative Example 3] 2% by weight iMv is 2 million ultra-high molecular weight polyethylene, 12 weight 123124.doc -34- 200831278 %2Mv is 150,000 high density polyethylene, 16% by weight 2Mv is 150,000 linear low density polyethylene 42.4% by weight of phthalic acid dioctyl vinegar* (DOP) and 17.6% by weight of fine powder of cerium oxide were mixed and granulated, and then mixed and extruded using a twin-screw extruder equipped with a T-die, and formed into The thickness is 9〇μπι< sheet shape. The DOP and the fine powder of cerium oxide are extracted and removed from the shaped product to form a microporous film. The two microporous membranes are overlapped and heated. Under the condition of 11 §, it extends 5.3 times in the longitudinal direction (extension speed is 1〇〇〇%/second), and then extends 1.8 times in the lateral direction (extension speed is 2%/second). 〇.96 πι, the membrane is a porous membrane of 22 μπι. Further, the dynamic thickness coefficient of the microporous membrane in the Td direction is (Κ7. The obtained polyolefin microporous membrane is cut by a coaxial slitting machine. 60 mm wide. d and L are 1〇2 mm and 1〇〇〇 m, respectively. Nineteen master rolls were cut to produce 176 rolls of polyolefin microporous film winding, and four windings were produced which produced a winding offset of 5 mm or more. Extract the 15 mm roll winding with a winding offset of less than 5 mm, measure and calculate d, • D, and ^. The result is: 1 > 193 ~ 200 mm, T is 21.1~23 · 2 μιη, t The maximum value of 21·5~23·8 μιη ' I Tt I is ι ·6 μπι, the standard deviation is 0.8 μιη ο ' Furthermore, the width of the mother roll is G.96 m wide, and the slitter is set. Extraction • The tension is 80 N, and the winding tension of the winding is • 40 N with respect to each rotating shaft, and the winding and tension control is not performed for each winding.

Evaluation of the insertability of the winding shell in the same manner as in Example 1, resulting in 5 rolls of defects ^ was regarded as poor D

[Example 4] 123124.doc -35- 200831278 144.0% by weight of 2Μν was 270,000 parts of polyethylene, 96% by weight of Mv was 3 million of ultra-molecular weight polyethylene, 56% by weight of phthalic acid After dioctyl ester (DOP) and 20% by weight of fine powder of cerium oxide are mixed and granulated, they are melt-kneaded using a twin-screw extruder equipped with a ruthenium mold at the front end, and then extruded, by a roller heated from both sides. Calendering is formed into a sheet having a thickness of 丨1〇μηη. The DOP and the fine powder of cerium oxide were extracted and removed from the molded product to prepare a microporous film. The microporous membrane was at 115. After the crucible was extended 5 to 5 times in the longitudinal direction, the heat treatment was finally performed at 120 °C. A microporous membrane having a lateral width of 〇·96 m, a film thickness of 30 μm, a porosity of 70%, and a pore diameter of 〇·ι μιη was obtained. The tensile strength of md is 190 MPa, the tensile strength of TD is 18 MPa, and the ratio of (MD tensile strength / TD tensile strength) is 1 〇·6. Further, the dynamic friction coefficient of the microporous film in the TD direction was 0.5. [Production of Polyolefin-Based Microporous Film Winding] The polyolefin microporous film produced by the above method was cut into a width of 6 mm and wound around a plastic tube (size, etc.) using a separate driving slitter. : 3B) Upper 'obtained polyolefin microporous film winding. d, l are 1〇2 mm, 1000 Hi 〇 cut 11 mother rolls, and 176 rolls of micro-porous micro-porous film windings are produced, and the windings that produce a winding offset of 5 mm or more are 2 volume. Extract 150 windings with a winding offset of less than 5 mm, measure and calculate D, D, and Shi'. The result is: 〇 is 214.2~2241! 1111, 1' is 27.9~31.20111, t is 28.2~ The maximum value of 32·5 μπι,| Tt| is 1·4 μπι, and the standard deviation is 〇·5 μπι. Further, the average value of F(5) is 25 N, and the average value of F(1〇)_F(2〇) is 2 N. 123124.doc -36- 200831278 [Preparation and evaluation of the electrode/separator winding material] According to the production of the electrode/separator winding of (3), an electrode/separator winding is produced, and then, according to the (4) electrode • The outer casing insertability of the separator winding was evaluated, and as a result, the defective product was 1, which was considered to be good. [Evaluation of the ease of damage of foreign materials by the polyolefin microporous film winding] One mother roll was prepared, and the outer diameter was measured in the width direction of the mother roll using the outer diameter measuring device shown in Fig. 2, and the diameter value was measured. Mark the mark near the maximum. Then, similarly to the production of the above-mentioned polyolefin microporous film wound, the mother roll was cut, and the cut polyolefin microporous film was wound, and when it was wound 100 m, the self-marking was marked. In the winding formed by winding the polyolefin microporous membrane taken near the place, insert the previously prepared 氧化 1 mm square oxidized section ' and continue cutting. After the coil was taken up, the wound material was unwound, and the pore state of the pores of the polyolefin microporous membrane produced by the alumina slicing was observed, and it was found that the openings were two layers. [Comparative Example 4] The polyolefin microporous film produced in Example 4 was cut into a width of 60 mm using a coaxial slitter. d and L are 1 〇 2 mm and 1 〇〇〇 m, respectively. 11 mother rolls were cut to produce 176 rolls of polyolefin microporous film windings, and 8 windings were produced which produced a winding offset of 5 mm or more. Extract 150 pieces of winding cut with a winding offset of less than 5 mm, measure and calculate D, T, and t. The result is: d is 214.5~223_5 mm, T is 28.0~31·〇123124.doc -37 - 200831278 μιη, t is 28.2~32.5 μηι, I Tt I has a maximum value of 1.9 μηη and a standard deviation of 0.5 μπι. Furthermore, the total width of the mother roll is 0.96 m wide, and the pulling tension of the slitter is 80 N ', and the winding tension of the winding relative to each rotating shaft is 4 〇N, not for each roll. The winding tension control is performed on the winding. The insert outer casing insertability was evaluated in the same manner as in Example 4, and as a result, 10 rolls of defects were produced, which was considered to be poor. Further, in the same manner as in Example 4, the polyolefin microporous film winding was evaluated for the ease of damage by foreign matter, and as a result, it was found that the openings were five layers. [Industrial Applicability] According to the polyolefin microporous film wound of the present invention and the method for producing the same, it is possible to provide an electrode/separator integrated winding which reduces insertion failure when inserted into a casing. It is preferably used for a separator for batteries, and is particularly preferably used for a large-sized lithium ion secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an example of a measuring device for the outer diameter of a wound material of the present invention. Fig. 2 is a schematic view showing an example of a measuring device for the outer diameter of the wound group of the present invention. Fig. 3 is a line diagram showing an example of results of simultaneous measurement of a plurality of windings. Fig. 4 is a schematic view showing a winding arm of an example of the manufacturing method of the present invention. Fig. 5 is a schematic view showing an example of a manufacturing method of the present invention. Fig. 6 is a schematic view showing a basic constitution of a mechanism for measuring the film thickness of a microporous film 123124.doc-38-200831278. Fig. 7 is a schematic view (front view) showing a preferred film thickness measuring device. Fig. 8 is a schematic view (front view) showing a preferred film thickness measuring device. Fig. 9 is a schematic view showing an example of a tightness measuring device for a wound material [Description of main components] 1A Optical size measuring machine projector - 1B Optical size measuring machine light receiving machine 2 Polyolefin microporous film winding Ring 3 Signal processing unit 5 Inspection result Output unit 6 Drive transmission unit 7 Timing belt 8 Pipe clamp head 9 Drive shaft 10 Gear • 11 Master roller 12 Polyolefin microporous film winding 13 Individual arm • 14 Cutter ... 21 Support table 22 Pillar 23 Sample stage 24 Measuring terminal rod 25 Measuring terminal rod Manual up and down indicator rod 123124.doc -39- 200831278 26 27 ^ 28 • 29 30 ^ 31 - 32 37 ❿ Analog display terminal parallelism adjustment member bearing Pressure adjustment portion optical detection portion fixing portion optical detection portion optical detection portion fixing portion height adjustment portion pressure adjustment portion fixing portion sample 123124.doc -40-

Claims (1)

200831278 X. Patent application scope: 1 . A polyolefin microporous film wound product, which is characterized in that it is a wound formed by winding a polycrystalline olefin microporous film on a winding core, and • The absolute value of the difference between the film thickness Τ(μηι) calculated according to the following formula (1) and the film thickness (μπι) evaluated for one piece (^ is 15 μmη or less, ^ T (pm)=7c(D2-d2)/4L (1) • (In the above formula (1), 'D is the outer diameter (mm) of the wound containing the porous film wound around the core, d system The outer diameter (mm) of the winding core, and l is the winding length (m) of the winding material. 2. The winding of claim 1 is manufactured by the following method. The polyolefin microporous film on the mother roll is cut into a specific width over its entire width, and then controlled by each of the wounds of the polyolefin microporous film cut into the specific width Winding is performed while winding up. The winding of claim 1 is cut by a separately driven cutter. The winding of any one of claims 1 to 3, wherein the tightness at 5 mm from the core is 34 N or less. 5. The winding of claim 4, wherein the tightness (F(l〇)) at a distance of 1 mm from the core and the tightness at a distance of 20 mm from the core (F(2〇)) The difference (F(10)-F(20)) is 0·05 Ν or more and 2N or less. 6. The wound article of any one of claims 1 to 3 having a roll length of 5 〇〇mw. The winding material according to any one of claims 1 to 3, wherein the polyolefin microporous 123124.doc 200831278 has a pore diameter of 0·0Ό1 μπι or more and 1 μπι or less, and a void ratio of 25% or more and 75% or less. The film thickness is 3 μπι or more and 200 μπι or less. The winding material according to any one of claims 1 to 3, wherein the polyolefin microporous film has a dynamic friction coefficient in the width direction of 0.6 or less. 9. The wound material according to any one of claims 1 to 3, wherein tensile strength (MD tensile strength) in the longitudinal direction and tensile strength (TD tensile strength) in the width direction of the polyolefin microporous film The ratio (MD tensile strength / TD tensile strength) is 10 or more. I. The winding of any one of claims 1 to 3 for use in a battery separator. The winding material according to any one of claims 1 to 3, which is used for a separator for a battery, and the pore diameter of the polyolefin microporous film is 0 · 〇〇1 μm or more and 1 μπι or less, void ratio It is 25% or more and 75% or less, and the film thickness is 3 μπι or more and 200 μηι or less. 12. A polyolefin microporous film wound group comprising two or more windings as claimed in claim 1 which are obtained by cutting a polyolefin microporous film wound on a mother roll. The winding group 'winding offset is $ mm to request the item! The standard deviation (10) of the film thickness difference _ 13 described in the above-mentioned article is characterized in that it is manufactured by the following method: 123124.doc 200831278 The winding group is wound on the mother roll The polyolefin microporous film is cut into a specific width over the total width thereof, and then controlled by the winding tension of each of the polyolefin microporous films cut into the specific width. Winding is performed on one side, and the winding deviation of each winding is within 5 mm, and the film thickness Τ (μπι) of each of the wounds calculated according to the following formula (1) is evaluated The standard deviation of the film thickness "difference (difference in film thickness) is 0 · 7 μηη or less, T (pm) = 7i (D2_d2) / 4L (1) (in the above formula, D means winding around the core The outer diameter (mm) of the wound material including the porous film, d means the outer diameter (mm) of the core, and l means the coil length (m) of the wound. 14. The group of coils of claim 12 which is cut by a separately driven cutter. The winding group according to any one of claims 12 to 14, wherein each of the polyolefin microporous film wounds has a roll length of 500 m or more. The winding group according to any one of claims 12 to 14, wherein the polyolefin microporous membrane has a pore diameter of 0.001 μm or more and 1 μm or less, and a void ratio of 25% or more and 75% or less, and the film thickness is 3 μπι or more 2 0 0 μπι or less. 17. The coiled article of any one of claims 12 to 14 for use in a separator for a battery. 18. The winding group according to any one of claims 12 to 14, which is used for a separator for a battery, and the pore control of the polyolefin microporous membrane of 123124.doc 200831278 is 0.001 μπι or more and 1 μπι or less. The void ratio is 25% or more and 75% or less, and the film thickness is 3 μηι or more and 200 μπι or less. 19. A method of producing a wound material according to the above claim, wherein a polyolefin microporous film wound on a mother roll is cut by a separate driven cutter to produce a polyolefin microporous film winding. And the film thickness μ(μιη) calculated according to the following formula (1) and the evaluation of one piece in the group of windings with a winding deviation of 5 mm or less in the total width of the mother roll The difference in film thickness Κμιη) (standard deviation of film thickness) is 〇7μηη or less, T(pm)=7i(D2 = d2)/4L (1) (In the above formula (1), D is wrapped around a roll. The outer diameter (mm) of the wound material including the porous film on the core is referred to as the outer diameter of the core, and [refers to the winding length (m) of the wound). A method for producing a polyolefin microporous film wound, comprising the steps of: cutting a polyolefin microporous film wound on a mother roll into a specific width over a total width thereof; and controlling one side The winding is performed while winding up the tension of each of the wound materials of the polyolefin microporous film cut into the specific width. A method for producing a polyolefin microporous film wound, comprising the steps of: cutting a polyolefin microporous film wound on a mother roll to a specific width in a total width thereof; and 123124. Doc 200831278 Winding while controlling the winding tension of each of the wound materials composed of the polyolefin microporous membranes cut to the specific width; wherein the polyolefin microporous film winding is wound The standard deviation of the difference between the film thickness μ(μιη) calculated according to the following formula (1) and the film thickness ΐ(μπι) evaluated for one piece (difference in film thickness) is 〇· 7 μπχ or less, Τ(μπι)=π(ϋ2-(12)/4Ε (1) (In the above formula (1), D means the outer diameter of the wound containing the porous film wound on the core ( Mm), d is the outer diameter (mm) of the core, and l is the winding length (m) of the winding. 22. The manufacturing method of claim 20, wherein the cutting is performed using a separate driven cutter. The manufacturing method of claim 20, wherein the film thickness of the polyolefin microporous film winding is calculated according to the following formula (1) (μηι ) The absolute value (μηι) of the difference (μηι) between the film and the film (μηι) evaluated for one piece is 1 · 5 μηη or less, Tbm) = 7i (D2-d2) / 4L (1) (below In the above formula (1), D means the outer diameter (mm) of the wound containing the porous film wound on the core, d means the outer diameter (mm) of the core, and l means the winding Volume length (m)). The manufacturing method according to any one of claims 19 to 23, wherein the polyolefin microporous film winding has a tightness of 5 N or less from the core of the winding of 34 N or less. The manufacturing method according to any one of claims 19 to 23, wherein the tightness (F(i〇)) at a distance of 10 mm from the core and the looseness at a distance of 2 mm from the core are 123124.doc 200831278 The difference (F(10)-F(20)) of the tightness (F(20)) is 0.05 N or more and 2 N or less. The production method according to any one of claims 19 to 23, wherein the polyolefin micro-β porous film winding has a roll length of 500 m or more. The production method according to any one of claims 19 to 23, wherein the polyolefin microporous membrane has a pore diameter of 0.001 μπι or more and 1 μηι or less, a porosity of 25% or more and 75% or less, and a film thickness of 3 μm. Above 200 μπι. The manufacturing method according to any one of claims 19 to 23, wherein the polyolefin microporous film has a dynamic friction coefficient in the width direction of 0.6 or less. The production method according to any one of claims 19 to 23, wherein the tensile strength (MD tensile strength) in the longitudinal direction and the tensile strength (TD tensile strength) in the width direction of the polyolefin microporous film are The ratio (MD tensile strength / TD tensile strength) is 10 or more. The production method according to any one of claims 19 to 23, wherein the polyolefin is a separator for a micro φ porous membrane battery. The production method according to any one of claims 19 to 23, wherein the polyolefin microporous membrane is a separator for a battery, and the polyolefin microporous membrane has a pore diameter of 0.001 μm or more and 1 μm or less. It is 25% or more and 75% or less, and the film thickness is 3 μηι or more and 2 0 0 μπι or less. 123124.doc